Two ambulance crews made “extensive efforts” to resuscitate the 39-year-old man, who remains in serious condition, following reports he had been drowning in the moat in Valence Park, Dagenham, yesterday morning.

Emergency workers found him lying on the ground in cardiac arrest, after possibly having been dragged out of the water by bystanders, and confirmed he began breathing again while in an ambulance on the way to Queen’s Hospital, Romford.

A London Ambulance Services (LAS) spokesperson said: “The patient was in cardiac arrest. The paramedics made extensive efforts to resuscitate him at the scene and on route to the hospital.

“They confirmed he started to breathe again in the ambulance.”

The LAS sent two ambulance crews, two responders in cars and a duty officer to the incident after getting the call at 11.15am.

A police spokesperson said the man “had found himself in difficulty while taking a ‘dip’ in the water”.

Police Supt Mike Hamer said: “It would appear that this incident was entirely avoidable. We understand that the parks are there to be enjoyed, but it is important that we all act responsibly around water of any depth.”

• Did you see what happened? Contact Freddy on 0208 477 3816 or email freddy.mayhew@archant.co.uk